NEW YORK (CNNMoney) -- The nation's extremely favorable mortgage rates sank even lower this week, setting records for both the 30-year and 15-year fixed rate loans.

The 30-year fell to 3.31% from 3.34% last week, according to Freddie Mac (FMCC, Fortune 500), the government controlled mortgage backer. The 15-year rate averaged 2.63%, compared with 2.65% a week ago.